package main


import (
"fmt"
"sync"
)

func test(t *sync.WaitGroup){
   
   fmt.Println("ok")
   t.Done()

}


func main(){
   wa := &sync.WaitGroup{}
   
   for i:=0;i<20;i++{
     wa.Add(1)
     go test(wa)

   }

   wa.Wait()
   
   fmt.Println("ok")
}



